Unloading mechanism



Nov. 16, 1943. E, LAMBERTON 2,334,633

UNLOADING MECHANISM Filed June 26, 1942 fizvenfar: RaZphELanzZern.

A; 4' WW awf Patented Nov. 16, 1943 V v HAN S f V f Ralph nra iiereamui mgmi cinema; assignry coiimany; n m-1;. :5 4

. e i ii imw p, Animation June is, 1942; Serial. 044851;

I 15'Claims.

This invention relates to pump unloading mechanisms-and more particularly to fluid actu ated unloading mechanisms for compressors; V, j

It is sometimes desirable that means he provided for unloading a compressor when difierent operating conditions exist. For example, when a mechanism other than the compressor is to be bieflobvious' that-neither the coaxial, arrangee driven by the same power unit that drives the compressor'and thepower unit-is unable to carry the; load of. both, then it may be-desirable that the compressor be unloaded Again when the compressor is being driven and. the discharge pressure reaches a predetermined; maximumvalue, the compressor should be unloaded. In order that each ofthese; functions may be eflectively i 7 performed, it, is desirable that separate operating devices, for example, expansible chamber type devices for operating the-valve which is to b moved to effect unloading, bepprovided-pand thesstructures and relations'of the parts aredesirably so'arranged that difierent operating media may beutilized, and media from different sources and at'difierent pressures. lt lis a-lso desirable that when one-devicehas acted to effect unload;- ing, the other may also-act inrsuch a manner that, upon cessation of action of the first the second may preclude reloading if this-would be undesirable g I Asan illustration, it-may be notedhthat with an internal combustion.engine-employed to drive anair compressor or otherpumpand to-operatea hoist, and with the-the hoist connectible at will to the engine; it would be, relatively undesirable in somev installations-to have a situation-where n ent the aligned "arrangernntenorlthe operration. of A one device through the other i's' ves'sen' tie], and thatg-eachfloperating m ans Ibe ary ranged-for direchcoaction with .tnevvaive orfifijr direct coactionwi'ndependntly' of. the other with a commontvalve moving'elemelht. 1

object .of this invenf'on isto mane-t proved unloading mechanism" for; 'a compressor; Another object is, to provldean improved unload:

' ing mec hanism adapted m te" actuated when different operating 'conditions exist 'for' unloading a compressor -Still. another object' is to provide an. improved fluidfactfia'ted unloadingmechanisn responding to pressure fluidyorl fi'uids supplied thereto on the occurrence of diflierentloperating conditions for unloading 'aivcompressor; Yet another object is, to provide an ir'nproved unloading mechanisni responsive to fluid, or difierent fluids, supplied under pressure fromdifierent sources for efiectinglunloadirm of 'a compressor. Other objects. of the", invention will hereinafter more .;iullvappe r." J a a a the" ac mpanyi drawing! in which' for purposes orillus rat'ontw 'rornis or thejlnverition he 'li c is n; 5111i, -11 7- f --F'ig'. 1 is1 a vertical crosssectional view through a? W kdc ab mn nr cy nd r with? v l im c sm3 8 m here i h; ill str th a re 'em omm "th .1i vent I Fig, 2 is a similar viewf bowing aiiothe" elm:- b di exitin will be plic'able t'o intake closure, to discharge venting",

the enginemight bedrivinav thecompressor un-,

thereto. In anotherembodimentl'illustratedfan arrangement efiective in a difierent manner to prevent an undesired reloading will; berdi'sclosed.

. In the illustrative embodimentashown coaxial valve operatingdevices one acting; when efiective, through the other willbedisclosed, butit will and to inletvalveopening"types or unloading sys tems, but i'o'rpurposesjofil1ustration'itwil1 s'uflice to.v show the same associated with, the last type prunlbadmg; v, 3 r

v I each. of, the; illustrative embodiments of r the invention. shown a con1 press'or;cylinder l provided witha bore v1" navinga; piston ,3 reciprocably mountedftherein; v Forme f the'cylinder coa'xiallyirvith the bore 2 is an e'nlarged bore 5 receivinga; valve mechanism, generally designated 6,.anda. cylinder head I; cylinderjhead is provided with aflange 8 whichiis'clamped'to the ng perv end llof" the cylinder; as by bolts 9f, and the lower. end of -thercylinder head rests: upon the valve mechanism andholds the latter firmly against ashoulder l I atj thefjunction between the bores- 2. and 5.v Extending, laterally" thl'o'ughith'e cylinder is ,an intake passage I!- communicating with a passage l5 which extends'thro'ugh the cylinder head} and the valve mechanis'mjfi into communication wmitnebbre 2; Formedlin' the valve mechanism is a discharge passage ll communicating with a'passage |8 extending laterally through the cylinder at the side of the latter 7 opposite the intake passage I4. Aninlet valve 20 controls the flow of fluid between the intake passage and the cylinder bore, and a discharge valve 2| controls the flow of fluid between the cylinder bore and the discharge passage H. The piston 3'is-cause'd to reciprocate by means not shown and fluid moves past the inlet valve into the cylinder bore andis then forced out past the discharge valve to the discharge passe i8.

an unloading mechanism, generally designated 24. This unloading mechanism includes a member 25 and plates 26 and 21 attached to the cylin-.

der head as by bolts 28. Formed .between'the.

area of the plunger portion 55 and hence the presence of fluid under pressure in the chamber 29 will not preclude the downward movement of the plunger 5| even if the operating pressure for the diaphragm be lower than that in chamber 29,

. understood when it is considered that if there 'be pressure supplied through passage 58 when Supported on the cylinder head I in Fig.4 is 3 pump discharge pressure reaches the desired maximum, .and thecompressor be unloaded, and

the engineerdecides to connect his hoist for drive V by the engine-and fluid is then automatically plate '21 and the member is a chamber 29 within which a reduced portion 30 of a plunger rods or fingers 38 'ext'ending throughopenings 39 r in the cylinder head into'the intake passage l5 where they are adaptedto engage the inlet valve to move the latterlfromgits s eat'and unload the compressor. The plunger 3| is normallyheld'in its raised:positionfbyf:a spring- 46 arranged in the recess 31. The spring" and'the plunger'are guided by a pini4| fixed to the cylinder head'and projecting upwardly through an opening in the spring into'a recess42 formed in the plunger. Surrounding the reduced portion 39 of the plunger just above the plate 26 is a packing 44 sealingly engaging the plunger for preventing the escape of pressure fluid from the chamber 29 into'the recess 31. -Mounted on the plate 21 are members 46 and 41 held by bolts 48 extending through openings inthe plate 21 and in a flange on the member 25. Formed betweenthe members 46 and 41 is a chamber 4 9,"and a flexibledia'phragm 561s received in this chamberand is clamped between the members 46 an'd'ffl'. Afplunger; 5| is arranged in the chamber 49 and hasan enlarged head52 which is held in engagement with the,diaphrag'm by a coiled springfl54; A reduced portion 55 of the plunger 5 ll jext endsr downwardly through openings in the member 41 and the plate 21 into the'chambei 29'.in .axi'al alinement with the plunger 3|. A packing '51 fits withina recess in the member" surrounding the reduced portion 55 and sealingly engages the latter for preventing escape of pressure fluid from the'chamber 29 to the chamber 49;;Communicating with the chamber 29 is a conduit 58 through whichpressure fluid may be supplied to act on the plunger 3| and force the latter downwardly. Communicating withthe chamber 49 at the upper side of the diaphragm 561s a'conduit59 through which pressure fluid may be supplied for forcing the diaphragmf50' downwardly and effecting an 'un; loading movement ofthe plunger 3| through the plungeril 'Ihe'sp'ace in the chamber 49beneath the diapln'agnr 5!! is vented to atmosphere through a vent port 66. It will be .seen that the unloading mechanism' is j'adapted to operate at; any time sure from the chamber 29, the compressor will still be held unloadedjan'd the load of the working compressor will not be thrown onto the then hoist actuating enginei v I Now referring tothe other illustrative embodiment of the invention and to FigureZ, it will be seen that attachedto' th'e cylinder head 1 is an unloading mechanism generally designated 64. This unloading mechanism comprises members 65 and 66 an'da plate-il'fixed-to the top of the cylinder headas bybolts 68. Formed between the members 65and 66 is a chamber 69, and a flexible diaphragm I0 clamped between the members 65 and 66 is movable within the chamber. A plunger projects through an opening in the plate 51 intothe chamber 69' and has an enlarged portion'lz 'received within a recess '13 formed in the cylinder head beneath the plate 61. Attached to-the portion 12 are rods or fingers 15 which extend through'op'enings I6'of the cylinder head into theintttke passage l5 and are engageable at their lower ends with the inlet valve 20 to move the latter from its seat and 'unloadthe compres- .sorcylinden A spring 11, shown herein as a bowed plate type spring' acts between the bottom of therecess 13 andthe plunger 1| to hold the latter normally in its upper position A guide 'surface'offthe diaphragm 10' to hold the latter normally in its raised position. Opening into the chamber 69 at the upper and lower sides of the diaphragm 10 are ports and 86 through which pressure fluid may be supplied for eiiecting actuation of the plunger 'I|-. Pressure fluid supplied through port 85 acts on the upper surface of the diaphragm to force the latter toward a lower position moving with it the plunger ll for unseating the inlet valve 20, thereby unloading the compressor cylinder: Pressure fluid supplied through the port 86 to the chamber 69 beneath the diaphragm 19 acts directly upon the plunger TI and moves the. latter to its unloading effecting position.

It willbe observed that the efiective area of the plunger H is comparatively small compared with that of the diaphragm and so, if the plunger 1| is held down by a dropping pressure as the pilot amass valve bleeds on the cqfl lptcssordisthargepressure fromwithin chamberjflqthrvueh t n gfifl hold the Lmloading fingers ineffective e e e a ure th n th t??? h t i so lowthat the inlet valve will "reclose and assume normal operation. If desired,:and indeed preferably, any suitable meansm 'yfbe provided I the escape of pressure fluid from -one-oisaid to enable fluid admitted "throug'hbassage as to I,

have immediate accessto alar'g'e'area qit'h'npper surface-of diaphragm it evenwhen the latter is in top"position." I I V As a resul't'of this invention, there isprovided an improved funloading mechanismfoperable to effect unloading'ofa compressor on 'theocjcurrence "of different operatlng conditionsg It will be notedthat the unloadingiinechanism is adapted to be operated by fluid pplied undenpresj sure to different pressure chambers, and anyone of the pressure chambers may be vented without effecting the operation oi thejmechanis'mbyfluid supplied to another or the pressure chambers. Different fluids; and similar fluids under different pressures may be used if desired, and by reason of'thefeatu'res of the invention, the desired automatic control of the load on the compressor While there are shown in thisv application two forms which my invention may assume in practice, it will be'underst'ood 'thatlthesefforms are shown "for purposes of illustration and that "the inventionmay be modified 'andfembodi'ed in various other forms without departingfrom its spirit 'or the scope of the appendedclaims. y

What I claim as new and desiref't'o secure by Letters'Pa'tent is: p

1. A compressor unloadingpinechanism,-comprising a lower chamber, annnloadingplunger extending within said chamber, valve means controlled by said" plunger "and movable to a position forefiectingunloadingmeans for supplying pressure fluid to .said chamber for acting on'said plunger and moving it in a direction to effect movement of said valve means to its unloading position, a chamber arranged above said lower chamber and containing a diaphragm dividing it into separate chamber spaces, a

plunger received within one of said chamber spaces and having a portion projecting downwardly into said lower chamber, means for yieldably holding said last mentioned plunger against said diaphragm, and means for supplying fluid under pressure to the other of said chamber spaces for forcing said diaphragm downwardly and moving said plungers in an unloading direction.

2. A compressor unloading mechanism comprising a lower chamber, an unloading plunger extending within said chamber, valve means controlled by said plunger and movable to a position for effecting unloading, means for supplying pressure fluid to said chamber for acting on said plunger and moving it in a direction to effect movement of said. valve means to its unloading position, a chamber arranged above said lower chamber and containing a diaphragm dividing it into separate chamber spaces, a plunger received within one of said cham- "chambers tothe fothe'r', andine'ans for supplying fluiilu'nder pressure to'theotherof said chamber i a r or i s d phragm downwardly and"- moving 'said 'l lungers in an unloading fdircctiqn;

A compressor unloading mechanism comjprising an upper and a lower chamber, an undlng' plunger eiitendingintc-said lower chainmanners-a" posi'tip'nffor effecting unloading, 7

means for supplying fto' sa'id' lower chamber a fluid under prcss'ufi'e for acting on said plunger -and movinggit infidiictibh'td effect movement *0! said valve mea s to its unloading position,

means .for yieldably urging saidplunger tow'ard said lower chamber, diaphragm clamped within said upper chamber and dividing the latter into upper and lower chamber spaces, a 1 plunger received 'v'vith in f said lower chamber space and having a reduced portion extending within' said lower-"chamber stave said unloading plunger, means sealingly engagmgsaia [reduced i'plunger portionior preventing the passing of" pressure fluid between said chambers, 'andmeans for sypplying a fluid under pressure to said upper chamber 'spa'ce'ionacting 'on said diaphragm and effectingmoveme ntp'i said plungers in an unloading direction." l

14, A 'compressor unloading mechanism comprising an i PDer and a lower chamber, an unloading plunger extending within" said lower chamber,"v'alve means controlledj-by said plunger and movable to a possessor effecting i unloading, means for supplyingpressure fluid to said lower 'ch'a'mb'er for forcing said plunger in a direction to el'fect movemen'tof said valve means to its unlo'ailing position, a "diaphragm clamped within said HD1 a e 5 diVidirigwhe' latter into upper andflower chamber spaces, means for transmitting an operating force from "said'illaphragm to s1aid--plunger, 'ineans for supplyingafluid under pressure to said upper'cha ber space, and means for venting said lower chamber space.

5. A compressor unloading"mechanism comprising a chamber, a diaphragm dividing said chamber into separate chamber spaces, an unloading plunger extending within one of said chamber spaces, valve means controlled by said plunger and movable to a position for efiecting unloading, means for supplying to said chamber space containing said plunger a fluid 'for acting on said plungerand moving it in a direction to effect movement of said valve means to its unloading position, and means for supplying to said other chamber space a fluid for acting on said diaphragm and efiecting 'movement of said be! spaces-and 'hfavingy'ag' portion projecting v downwardly lnto said-lower chamber in -anal d unloadln'g plungcr',-meins sea sign engaging the projecting "portion-fol? san la'stY mentioned plunger for 1 preventing it in a directionto eflectrnovementof said valv e means to its unloading position, and means i'or. i, supplying to said other chamber space a, fluid under pressure tor acting on "saiddiaphr agmfand effecting movement of said plunger in an unlgad-r ing direction, I U a I 1 7. In a compressor.unloadingi mechar ism, in combination, an unloading plunger, a chamber receivinga portion or said unloading plunger,

valve means controlledby said plunger and mov valvemeans controlled, by said plunger andmovable-to a position for effecting unloading, means for supplying a pressure fluid to said chamber for .forcing said plunger, in a direction to efiectmoyement of .said valve means to its unloading posi- 11. In a pump unloadingmechanism, incombination, avalve movableto effect unloading, a plurality of fluid. operateddevices for actuating said yalve, said actuating devices operable each byfluidsupplied thereto independently of fluid ,supplyto any other, and means for conducting operating fluidto and venting fluid'from said actuating device s, I

1 2. In a pumpunloading mechanism, in combination valve means movable. to effect unloading jot. a pump, and operating means for said valve means including fluid operated actuating devices for said valve means independently suption, means including afdiaphragm supported above said plunger for transmittinganoperating force to said plunger, and means for supplying pressure fluid to said diaphragm, 9. In a pump unloading mechanism, in combination, a ,valvemovable to unload a pump, means for transmitting movement to said valve to move it to unloading position, a-plurality of means each operative independently otoperating medium supply to any other, upon operating medium supply thereto, to move said movement transmitting" means to effectunloading,v and means for conducting operating medium to said last mentioned means. i

10. In a pump unloading mechanismJn combination, a valve movable to unload a pump, means for transmitting movement to said, valve to move it=to,unloading position, a plurality of means each operativeindependently of operating medium supply to any other, upon operating medium supply thereto, and one exerting its force through the other, to move said movement 7 transmitting means to effect unloading, and

means for conducting operating medium to said last mentioned means.

pliable "with operating fluid, one of said devices superimposed .on the other, and said devices having'separate sources of operating fluid.

. 13. In 'a' pump unloading mechanism, in combination, valve means movable to effect unloading of aipump,v and operatingmeans for said valve means including fluid. operated actuating devices for said valve means, one device exerting its valve means operating force through the other of operating fluid. a I V .lfialn' a pump unloading mechanism, in combination, a valve movable to effect unloading, a plurality of actuating meansior said valve, said actuating means each being responsive to the action of an operatingmedium, and having a valveactua'ting elementin common, and inde- Qdevice, and, said devices having separatesources pendent means for delivering operating medium to said actuating means whereby each may be actuated by its operating medium independently of operating medium delivery to any other.

15. In combination, valve means whose positioning determines whether or not a pump is loaded, meansfor transmitting movement to said valve means to move it from one operating position'to another, a plurality of means. for moving said movement-transmitting means to effect movement of said valve means, each of said plurality of moving means operative on operating medium supply'thereto to effect valve means movement and one operative on fluid operating medium supply thereto tomove andrto exert its force through the other, and'means for conducting operating medium.separately to said means for moving, said movement-transmitting means,

RALPH E. LAMBERTON. 

